Finite-Size Scaling Study of Aging during Coarsening in Non-Conserved Ising Model: The case of zero temperature quench.

Following quenches from random initial configurations to zero temperature, we study aging during evolution of the ferromagnetic (nonconserved) Ising model towards equilibrium, via Monte Carlo simulations of very large systems, in space dimensions $d=2$ and $3$. Results for the two-time autocorrelations, obtained by using different acceptance probabilities for the spin-flip trial moves, are in agreement with each other. We demonstrate the scaling of this quantity with respect to $\ell/\ell_w$, where $\ell$ and $\ell_w$ are the average domain sizes at $t$ and $t_w$ $(\leqslant t)$, the observation and waiting times, respectively. The scaling functions are shown to be of power-law type for $\ell/\ell_{w} \rightarrow \infty$. The exponents of these power-laws have been estimated via the finite-size scaling analyses and discussed with reference to the available results from non-zero temperatures. While in $d=2$ we do not observe any temperature dependence, in the case of $d=3$ the outcome for quench to zero temperature is very different from the available results for high temperature and violates a lower bound, which we explain via structural consideration. We also present results on the freezing phenomena that this model exhibits at zero temperature. Furthermore, from simulations of extremely large system, thereby avoiding the freezing effect, it has been confirmed that the growth of average domain size in $d=3$, that remained a puzzle in the literature, follows the Lifshitz-Allen-Cahn law in the asymptotic limit.